Water heater arrangement

ABSTRACT

A water heater arrangement comprising a gas-operated water heater device ( 1 ) that has an cold water inlet pipeline ( 2 ) and an hot water outlet pipeline ( 3 ), and which further comprises a storage type electric water heater ( 4 ) inserted serially into the hot water outlet pipeline ( 3 ), and which is equipped with a thermostat ( 5 ). In an embodiment it absorbs and utilizes the waste heat of the gas-operated water heater device ( 1 ).

This invention is relating to a water heater arrangement for servingutility hot water outlets, which includes a gas-operated water heater ora combined circulation heater and water heater means that has a coldwater inlet and a warm water outlet pipeline.

At homes and in places of small hot water demand, gas water heaters aregenerally used. Among them we can find circulator types that areoperated by water flow evoked by opening of a hot water tap at awater-taking spot. Heating of water included in the pipe section betweenthe water heater and the spot of water taking, as well as slow start ofheat transfer for heating at the beginning of the flow causes that evenfor a relatively long time, only cold or not sufficiently heated waterreaches the spot of water taking. This disadvantage is annoyingespecially in case of intention to take a small amount of hot water,when in time and in water there is a large wasted and practically notutilised amount. Devices generally at the start of water flow begin towork with maximum gas burner power, which however may lead tooverheating after the mentioned initial period, and this can also beannoying, e.g. at, the next opening that is repeated within a shorttime, where the user does not anticipate overheated water.

Moreover, gas-operated storage heater boilers—that include a built-inbuffer container—are also used. Hot water is transferred to the place ofwater taking from this buffer container. The container is heated in acontrolled way, what results in a more smooth gas burner powerconsumption characteristic. If the size of the buffer container is smallthen this does not significantly increase the dimensions of the device,but hot water will run out quickly. If the buffer container is largethen run-out will occur later, but gas energy used for heating mayappear as superfluous if no hot water is taken for a long time. Thisdisadvantage can be reduced by increasing the heat insulation, which maylead to increase of cost.

It is also possible to use a buffer container placed out of the device,by which the dimensions of the device will not increase, but to reachthe controlled temperature a separate circulation pump must be used,which is also costly.

These solutions have a common disadvantage that in case of absence ofgas supply they do not provide any hot water, or only with a largebuffer container are suitable for a more significant temporary hot watersupply.

Another frequent category of water heaters uses electric heating, and inthe heat insulated device container it stores stand by hot water ofcontrolled temperature. Its advantage is the possibility of simply andcheap accomplishment of temperature regulation. Its disadvantage is,however, that generally they require more space than circulation gasdevices and consume significant electric power. A further disadvantageis that in case of longer power cuts there is not hot water supply.

The object of this invention to find a solution that even in case oftaking frequently or only small amounts of hot water eliminates thedelay effect, and at the same time it is of favourable energyconsumption, requires little initial investment and is operable even inthe absence of considerable energy supply.

The invention is based on the recognition that it can be combined theadvantages of gas-operated water heaters with the advantages of electricwater heaters of small-size container, and with this arrangement it canbe achieved optimal operation and practically unchanged overall devicesize.

A further advantage of this arrangement is elimination of the effectoccurring while taking very small amount of hot water, when due to thesmall amount the gas water heater does not start automatically, and eveninto the storage heater container only cold water flows in, which aftermany small takings stores only cold water. In the solution applied byus, however, the electric storage heater boiler constantly heats thewater until reaching the preset temperature, that is during the pausesbetween the short intervals. Thereby it provides both the heat balanceand minimization of the size of the container.

The object of the invention is achieved by a water heater according tothe introductory paragraph, in which a storage type electric waterheater is inserted serially into the hot water outlet pipeline, whichelectric water heater is equipped with a thermostat.

Further we present the invention by drawings, where

FIG. 1 is a gas-operated water heater device with electric water heateraccording to the invention, connected from outside,

FIG. 2 is a gas-operated water heater device with electric water heateraccording to the invention, connected in built-in way.

In FIG. 1 an optional gas-operated circulation water heater device 1 isshown. The gas-operated water heater device 1 has a cold water inletpipeline 2 and a hot water outlet pipeline 3. Into the latter, in serialarrangement, an electric water heater 4 according to theinvention—outside connected to the previous part—is inserted. Theelectric water heater 4 has an electric connector 8 connected to aheating wire as well as a thermostat 5 that detects the temperature ofthe stored puffer water and controls the heating wire accordingly.According to FIG. 1 the electric water heater 4 is inserted into the hotwater outlet pipeline 3 outside of the gas-operated circulation waterheater device 1 but in its close vicinity. This arrangement can beadvantageous from the point of view of effective utilization of space.In such a case, it can be expedient to cover the container of theelectric water heater 4 by heat insulating material, because due to itsexternal placement it is not contacted with significant amount ofavailable extra heat. The electric water heater 4 can be placed evenfurther from the gas-operated circulation water heater device 1 in thehot water pipeline towards the water taking spot.

In case of another embodiment, which is shown in FIG. 2, the electricwater heater is built-in into the gas-operated circulation water heaterdevice 1. Its advantage is that it is not necessary to lead ordisassemble the hot water pipeline. Its another advantage can be that incase of proper design and placement the buffer storage container of theelectric water heater 4 can utilize the waste heat otherwise non-usablethat evolves in the gas-operated circulation water heater device. Forthis purpose we can use a heat transfer element that penetrates into thecombustion space 7 of the gas-operated circulation water heater device1, and by heat transfer it preheats the water amount included in theelectric water heater 4, thereby reducing the amount of electric energynecessary for heating to a preset minimum temperature. This heating isperformed in a controlled way, i.e. the thermostat 5 keeps the waterincluded in the electric water heater 4, that is in the buffercontainer.

It is enough to choose a low storage capacity for the electric waterheater 4 that works as a buffer container, because it serves basicallyfor compensation of temperature delay and overshoot of the gas-operatedsingle water heater or combined circulation water heater device 1. Forthis generally it is enough to apply a buffer container smaller than 20litres, e.g. 5-15 litres. Yet with such buffer volumes we get at thespot of water taking a completely steady temperature that is adjustableby the thermostat 5 of the electric water heater 4. The electric waterheater 4 heats the system also in the period beyond taking water,therefore a small-size container is sufficient. We can choose thistemperature also for relatively low, this will not prevent that possiblymuch hotter water supplied by the gas-operated water heater device 1with some time delay, will also reach the water taking spot. When thetap at the water taking spot is closed, the water remaining in thecontainer of the electric water heater 4 will be of higher temperaturethan it is preset by the thermostat 5. Then, until cooling back thewater included in the buffer container the operation of electric heatingis not required. By this we can achieve favourable energy consumption,environment-friendly operation.

By the arrangement according to the invention it can be provided that incase of absence of gas or heavy electric current there is a possibilityfor taking of utility hot water. At the same time, disadvantageous delayof gas-operated water heating with more favourable economy is alsoeliminated, because water included in the buffer container of electricheating balances slow reaction in temperature or overheating either incase of single water heater or combined circulation water heaterdevices. Buffer container of electric heating with a relatively smallsize will increase dimensions to a little extent only and consumeslittle electric energy. In case of integration with the gas-operateddevice the buffer container does not require significant heatinsulation.

LIST OF REFERENCES

1 gas-operated water heater device

2 cold water inlet pipeline

3 hot water outlet pipeline

4 electric water heater

5 thermostat

6 heat transfer element

7 combustion space

8 electric connector

1. Water heater arrangement with a gas-operated water heater device thatis connected to a cold water inlet pipeline and to a hot water outletpipeline, characterized in that it further comprises a storage typeelectric water heater inserted serially into the hot water outletpipeline, and which is equipped with a thermostat.
 2. Arrangementaccording to claim 1, characterized in that the electric water heater isbuilt into the gas-operated water heater device.
 3. Arrangementaccording to claim 1, characterized in that the electric water heater isoutside connected to the gas-operated water heater device. 4.Arrangement according to claim 1, characterized in that storagecontainer of the electric water heater is of a storage volume of lessthan 20 litres.
 5. Arrangement according to claim 2, characterized inthat the electric water heater is built inside the gas-operated waterheater device in order to absorb and utilize its waste heat. 6.Arrangement according to claim 5, characterized in that the electricwater heater is built into the gas-operated water heater device with aheat transfer element that penetrates into its combustion space. 7.Arrangement according to any of claims 1-6, characterized in _(t)hat thecontainer of the electric water heater is covered by heat insulationmaterial.